build: greatly speed up build times using pch

CMakeLists.txt

@@ -1,5 +1,5 @@
 cmake_minimum_required(VERSION 3.20)
-project(quickshell VERSION "0.1.0")
+project(quickshell VERSION "0.1.0" LANGUAGES CXX C)
 
 set(QT_MIN_VERSION "6.6.0")
 set(CMAKE_CXX_STANDARD 20)
@@ -65,6 +65,28 @@ find_package(Qt6 REQUIRED COMPONENTS ${QT_FPDEPS})
 qt_standard_project_setup(REQUIRES 6.6)
 set(QT_QML_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/qml_modules)
 
+file(GENERATE
+	OUTPUT ${CMAKE_CURRENT_BINARY_DIR}/pchstub.cpp
+	CONTENT ""
+)
+
+add_library(qt-pch ${CMAKE_CURRENT_BINARY_DIR}/pchstub.cpp)
+target_link_libraries(qt-pch PRIVATE ${QT_DEPS})
+target_precompile_headers(qt-pch PUBLIC
+	<memory>
+	<qobject.h>
+	<qqmlengine.h>
+	<qlist.h>
+	<qcolor.h>
+	<qquickitem.h>
+	<qevent.h>
+)
+
+function (qs_pch target)
+	target_precompile_headers(${target} REUSE_FROM qt-pch)
+	target_link_libraries(${target} PRIVATE ${QT_DEPS}) # required for gcc to accept the pch on plugin targets
+endfunction()
+
 add_subdirectory(src/core)
 add_subdirectory(src/io)
 

README.md

@@ -47,6 +47,8 @@ This repo has a nix flake you can use to install the package directly:
 Quickshell's binary is available at `quickshell.packages.<system>.default` to be added to
 lists such as `environment.systemPackages` or `home.packages`.
 
+Note: by default this package is built with clang as it is significantly faster.
+
 ## Manual
 
 If not using nix, you'll have to build from source.

default.nix

@@ -3,7 +3,7 @@
   nix-gitignore,
   pkgs,
   keepDebugInfo,
-  stdenv ? (keepDebugInfo pkgs.stdenv),
+  buildStdenv ? pkgs.clang17Stdenv,
 
   cmake,
   ninja,
@@ -23,7 +23,7 @@
      else "unknown"),
   debug ? false,
   enableWayland ? true,
-}: stdenv.mkDerivation {
+}: buildStdenv.mkDerivation {
   pname = "quickshell${lib.optionalString debug "-debug"}";
   version = "0.1.0";
   src = nix-gitignore.gitignoreSource "/docs\n/examples\n" ./.;

shell.nix

@@ -10,7 +10,7 @@
     rev = "1f062cc198d1112d13e5128fa1f2ee3dbffe613b";
     sha256 = "kbt0Zc1qHE5fhqBkKz8iue+B+ZANjF1AR/RdgmX1r0I=";
   }) { inherit pkgs; };
-in pkgs.mkShell {
+in pkgs.mkShell.override { stdenv = quickshell.stdenv; } {
   inputsFrom = [ quickshell ];
 
   nativeBuildInputs = with pkgs; [

src/core/CMakeLists.txt

@@ -22,6 +22,7 @@ set_source_files_properties(main.cpp PROPERTIES COMPILE_DEFINITIONS GIT_REVISION
 qt_add_qml_module(quickshell URI Quickshell VERSION 0.1)
 
 target_link_libraries(quickshell PRIVATE ${QT_DEPS})
+qs_pch(quickshell)
 
 if (BUILD_TESTING)
 	add_subdirectory(test)

src/io/CMakeLists.txt

@@ -16,6 +16,10 @@ target_link_libraries(quickshell-io-init PRIVATE ${QT_DEPS})
 
 target_link_libraries(quickshell PRIVATE quickshell-ioplugin quickshell-io-init)
 
+qs_pch(quickshell-io)
+qs_pch(quickshell-ioplugin)
+qs_pch(quickshell-io-init)
+
 if (BUILD_TESTING)
 	add_subdirectory(test)
 endif()

src/wayland/CMakeLists.txt

@@ -37,9 +37,15 @@ function (wl_proto target name path)
 	execute_process(COMMAND ${qtwaylandscanner} client-header ${path} OUTPUT_FILE ${PROTO_BUILD_PATH}/qwayland-${name}.h)
 	execute_process(COMMAND ${qtwaylandscanner} client-code ${path} OUTPUT_FILE ${PROTO_BUILD_PATH}/qwayland-${name}.cpp)
 
-	target_sources(${target} PRIVATE ${PROTO_BUILD_PATH}/wayland-${name}.c)
-	target_sources(${target} PRIVATE ${PROTO_BUILD_PATH}/qwayland-${name}.cpp)
-	target_include_directories(${target} PRIVATE ${PROTO_BUILD_PATH})
+	add_library(wl-proto-${name}
+		${PROTO_BUILD_PATH}/wayland-${name}.c
+		${PROTO_BUILD_PATH}/qwayland-${name}.cpp
+	)
+
+	target_include_directories(wl-proto-${name} INTERFACE ${PROTO_BUILD_PATH})
+	target_link_libraries(wl-proto-${name} Qt6::WaylandClient Qt6::WaylandClientPrivate)
+
+	target_link_libraries(${target} PRIVATE wl-proto-${name})
 endfunction()
 
 # -----
@@ -65,4 +71,8 @@ endif()
 target_link_libraries(quickshell-wayland PRIVATE ${QT_DEPS})
 target_link_libraries(quickshell-wayland-init PRIVATE ${QT_DEPS})
 
+qs_pch(quickshell-wayland)
+qs_pch(quickshell-waylandplugin)
+qs_pch(quickshell-wayland-init)
+
 target_link_libraries(quickshell PRIVATE quickshell-waylandplugin quickshell-wayland-init)

src/wayland/session_lock/CMakeLists.txt

@@ -8,5 +8,6 @@ qt_add_library(quickshell-wayland-sessionlock STATIC
 
 wl_proto(quickshell-wayland-sessionlock ext-session-lock-v1 "${WAYLAND_PROTOCOLS}/staging/ext-session-lock/ext-session-lock-v1.xml")
 target_link_libraries(quickshell-wayland-sessionlock PRIVATE ${QT_DEPS} wayland-client)
+qs_pch(quickshell-wayland-sessionlock)
 
 target_link_libraries(quickshell-wayland PRIVATE quickshell-wayland-sessionlock)

src/wayland/wlr_layershell/CMakeLists.txt

@@ -9,4 +9,7 @@ qt_add_qml_module(quickshell-wayland-layershell URI Quickshell.Wayland._WlrLayer
 wl_proto(quickshell-wayland-layershell wlr-layer-shell-unstable-v1 "${CMAKE_CURRENT_SOURCE_DIR}/wlr-layer-shell-unstable-v1.xml")
 target_link_libraries(quickshell-wayland-layershell PRIVATE ${QT_DEPS} wayland-client)
 
+qs_pch(quickshell-wayland-layershell)
+qs_pch(quickshell-wayland-layershellplugin)
+
 target_link_libraries(quickshell-wayland PRIVATE quickshell-wayland-layershellplugin)